In one phase of this project the distribution and vector potential of Ixodes species that occur in the western coastal states are under study. Special emphasis has been placed on such tick-borne zoonoses of public health importance and a series of new and previously unreported viruses associated with ixodid ticks and seabirds on the Oregon coast. Another phase comprises studies of the distribution and vector relationships of viruses isolated from argasid (soft-shelled) ticks. Both phases may involve isolation and characterization of field- isolated viruses and laboratory transmission studies of the vector potential of certain ticks.